package com.haixin.test.interceptor;

import com.haixin.test.entity.User;
import org.springframework.web.servlet.HandlerInterceptor;
import org.springframework.web.servlet.ModelAndView;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;

public class AdminInterceptor implements HandlerInterceptor {
    /**
     * 在请求处理之前进行调用
     */
    @Override
    public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
        try{
            // 从session中获取user
            User user = (User) request.getSession().getAttribute("User");
            if(user != null){
                return true;
            }
            // 获取失败，返回登陆页面
            response.sendRedirect(request.getContextPath()+"helloWorld");
        }catch (IOException e){
            e.printStackTrace();
        }
        return false;
    }

    /**
     * 请求处理之后进行调用，但是在视图被渲染之前
     * @param request
     * @param response
     * @param handler
     * @param modelAndView
     * @throws Exception
     */
    @Override
    public void postHandle(HttpServletRequest request, HttpServletResponse response, Object handler, ModelAndView modelAndView) throws Exception {

    }

    /**
     * 在整个请求结束之后被调用，也就是在DispatcherServlet 渲染了对应的视图之后执行（主要是用于进行资源清理工作）
     */
    @Override
    public void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object handler, Exception ex) throws Exception {

    }
}
